日粮中外源纤维素酶添加水平对舍饲牦牛屠宰性能和肉品质的影响

Effects of Exogenous Fibrolytic Enzymes Levels in Diet on Slaughter Performance and Meat Quality with Housing-feeding Yaks

【目的】本试验旨在探究不同外源纤维素酶(Exogenous Fibrolytic Enzymes,EFE)添加水平对舍饲牦牛体尺指标、屠宰性能、器官指数和肉品质的影响。【方法】采用单因素试验设计,试验因素为EFE的添加水平(0、0.2、0.4 g/kg日粮干物质),选取24头年龄为4周岁左右的麦洼公牦牛,根据体重按照随机区组试验设计分为3个处理组(分别记为Con+0,Con+0.2和Con+0.4组),每个处理8个重复,每个重复1头牛。【结果】结果表明:(1)Con+0.2和Con+0.4组牦牛的胸围显著高于对照组(P=0.01),Con+0.4组的体高有高于其余两组的趋势(P=0.09);(2)Con+0.4组牦牛的肉骨比(P=0.066)和净肉率(P=0.072)有高于对照组的趋势;(3)随着EFE添加量的提高,牦牛的瘤胃的器官指数随之提高(P=0.006);(4)各处理牦牛肌肉p H值熟肉率、滴水损失率和常规营养指标差异均不显著(P>0.05);(5)Con+0.4组牦牛的肌肉胱氨酸含量显著低于其余2组(P=0.025),但脯氨酸含量则显著高于其余两组(P=0.015)。【结论】因此,本试验条件下,日粮中EFE提高了牦牛胸围和净肉率,对肉质无显著影响,以0.4g/kg的添加量较优。

[ Objective] The objective of this study was to delve into the effects of exogenous fibrolytic enzymes （ Exogenous fibrolytic enzymes, EFE） supplementary level on the body size, slaughter performance, organ index and meat quality with housing-feeding yaks. [ Method ] Sin- gle factor experiment design was used, and the factor was the supplementary level of EFE （0, 0.2,0.4 g/kg DM ）, and 24 4-year-old Mai- wa male yaks were divided into 3 treatments （ Con ＋ 0, Con ＋ 0.2, Con ＋ 0.4 ） according to randomized block design, with 8 replicates of 1 yak. [ Result] （i） The circumference of Con ＋ 0.2 and Con ＋ 0.4 groups of yaks was significantly higher than the control group （ P = 0. 01 ）, and there was a trend of increasing withers height compared with others ; （ii） There was a trend of increasing the meat/bone ratio （ P = 0. 066） and net meat rate （ P = 0. 072） of yaks by EFE supplementation （ Con ＋ 0.4 group） ; （iii） With the increasing of EFE dose, organ index of the rumen of yak increased （P = 0. 006） ; （iv）No difference were found with the pH value, cooked meat rate, water loss rate and conventional nutrient component of muscle in all treatments; （v） the cystine content in muscle of yak in Con ＋ 0.4 group was lower than anther groups （P = 0. 025 ）, but the proline content was greater （P = 0. 015 ）. [ Conclusion ] Under the conditions of this experiment, E FE supplementation in diet of yaks increased the circumference and net meat rate, and no significant effect on the meat quality, and the dose of 0.4 g/kg was better.